I trapped two errant moles recently that had invaded my garden from an adjacent field and taken to tunnelling under my flower beds and lawn, leaving small mole hills behind them.

I would have gladly let them get on with their subterranean lives if it hadn't been for the mess they were making on the lawn, and the daffodil bulbs they were pushing to the surface in the flower borders.

Fortunately, being a retired farmer, trapping them was a relatively simple task for me. The only snag was that I had sold my mole traps at my farm sale and had to buy a couple of new ones.

Loading article content

My father taught me how to set mole traps when I was a young schoolboy, and then encouraged me to hone my skills by paying sixpence for every mole that I caught.

Mole traps should be set in the main tunnels, or runs as we call them, that are usually located close to drystane dykes, under the bottom wire of a fence, or just above a sheep track on steep ground.

Moles aren't daft and tunnel their main runs where they are unlikely to be trampled by the hooves of grazing cattle or sheep. Another favourite run to trap is the one that heads to water, because moles have to drink regularly.

Runs to avoid setting traps in are the shallow ones dug for feeding, as they are soon abandoned.

Readers may be wondering why farmers want to kill harmless little creatures that spend all their time underground and out of sight, and, unlike rats and mice, never nibble farm produce like grain. The answer is simple – the hillocks left behind as a result of their tunnelling contain small stones that cause expensive breakdowns with mowers and silage-making equipment.

Worse, soil from those mole hills contaminates the silage and leads to a fatal disease in sheep called listeriosis.

Setting traps and checking them regularly takes valuable time, so most of us started to use the deadly poison, strychnine. It killed moles within seconds and was a breakthrough when it became available, but could only be obtained under licence. To get that licence we had to go on special training courses, run by the local agricultural college, that taught us how to use it safely.

Every year we applied for a permit to buy small quantities at the local chemist that we then kept securely locked up until it was used.

We sprinkled small amounts of the poison over a bunch of worms and then placed them individually into the same main runs we used to prefer to set traps in.

The idea was to gather worms left on the surface behind a plough. That was backbreaking work, but much easier than digging them by hand. You can pour liquid concoctions, such as soapy water, over grassland to encourage worms to the surface, but moles are gourmets and ignored such tainted bait.

Even fresh worms gathered from behind a plough on a different farm, had to be left for a few days in a barrel filled with soil gathered from molehills on the farm to be baited. That was the only way to convince them that they were their normal fare.

However, strychnine was withdrawn from use in 2006 under an EU directive on human and environmental protection standards.

Since then, some farmers have resorted to using tablets containing aluminium phosphide that give off a deadly gas when placed in mole runs. As with strychnine you need to be properly trained in their use.

Others have gone back to trapping, and hiring retired shepherds, farm workers and gamekeepers to do the time-consuming task, as happened in my father's day.

As in those days, that can create a very useful addition to a pension.

Mole trappers used to advertise their skill by hanging the moles they had caught, by the head, from the barbed wire on the top of a fence in full view of the main road.

I remember a retired shepherd in my area who impressed all the locals with an incredibly long line of trophies, until he was found out. The "moles" on display in the near-distance, on closer inspection, were found to be small pieces of black polythene, filled with soil and shaped to look like a mole hanging from the barbed wire.